Certain Government Agencies and their contractors have in recent years produced and tested fuel-air type bombs, also known as FAE devices, all of which have had critical disadvantages. The early bombs tested have carried either pressurized propane or ethylene oxide as fuel to provide the ultimate explosive effect, when mixed with air. The fuel was dispersed into the air by means of a high brisance explosive. Fuel dispersal by means of a high brisance explosive resulted in the formation of a doughnut shaped cloud of fuel-air mixture which cannot be efficiently detonated by detonators located in its void central area. For this reason such bombs necessarily have had to carry numerous cloud detonators, together with a means for distributing these detonators into various locations within the surrounding doughnut shaped cloud prior to actuating the detonators. Since the downward velocity of travel of the bomb hardware, after fuel dispersal, is much greater than that of the doughnut shaped cloud, it has not been possible to properly distribute the detonators into the doughnut shaped fuel-air mixture without retarding the terminal velocity of the bomb. By reason of this limitation, the bombs must use a parachute or other speed retarding device prior to target impact.
Such parachute lowered bombs are subject to wind drift, enemy detection and dispersal prior to bomb detonation, hanging up in the trees, etc.
Another type of two event FAE device, covered in our U.S. patent application Ser. No. 89,140, utilizes a low brisance central burster explosive with an unpressurized monopropellant liquid fuel which is stable in the liquid state but highly explosive when atomized in the air. By using a low brisance burster charge the cloud formation is not torus shaped but rather hemispherical with a substantially uniform fuel-air density. With a uniform cloud the second event detonation can be handled with a single or dual detonator rather than the complex multiple detonator system previously mentioned.